Many people believe we are heading for environmental disaster _____we radically(彻底地) change the way we live.
________ the words,the daughter understood what her mother was trying to tell her.
This vase ________ perfect but for a few small holes in its base.
Tom sacrificed his personal life ________ he could get ahead in his career.
There is still a strong argument ________ mobile phones are a particular risk to children.
Students ________ remain in their seats until all the papers have been collected.